ANKARA (Reuters) - Turkey and Russia are discussing opening Russian-controlled air space in Syria's Idlib region for armed and unarmed drones, Turkish Defence Minister Hulusi Akar was quoted as saying on Thursday, but he added that problems over the issue persisted.

Speaking to reporters in parliament, Akar said Ankara was "hopeful" about ongoing talks between Turkish and Russian officials in Ankara over the northwestern Idlib region, where Turkey's military is backing Syrian rebels against government forces backed by Russia.

Akar also said he would speak with U.S. Secretary of Defence Mark Esper by telephone later on Thursday, broadcaster NTV said.